“What can the President do with a country of crazies who could surprise the world with a terrible atrocity in a suitcase?”
The Israeli solution is now the only solution. Bomb the infrastructure. Force them to give up all fissionable materials. (This has been made extremely difficult by Russia which has supplied the latest first world anti-aircraft technology and the fact that we have to supply troops in Afghanistan. Bombing Iran probably means abandoning Afghanistan, because we rely on Muslim countries to let us use their air space.)
As far as is known Russia only supplied the S-300 missiles, not the radars, nor the training to use them.
Sooner or later all Islamic countries will have to be abandoned, else they will have to give up Islam - there is no alternative short of nuking Mecca and Media during the Haj without warning to utterly destroy Islam forever.